1. Field of the Invention
The present invention relates to a data input device for a computer and, in particular, to a device which enables inputting three-dimensional data into a computer.
2. Description of the Prior Art
As data input devices for computers, pointing devices, such as mice and digitizers, have been widely used cooperatively with keyboards. FIG. 15 is a diagram for explaining how to use a conventional mouse C as an example of the pointing devices. As shown in the figure, the mouse C is connected to a data input section of a computer B via a given mouse interface. Through the software in the computer B, displacement magnitudes of n pointer (or a pointed object) in the horizontal (x-axis) and vertical (z-axis) directions on the screen are controlled to correspond to displacement magnitudes of the mouse C in the leftward/rightward (x-axis) and forward/backward (z-axis) directions on the desk. Accordingly when an operator moves the mouse C in a desired direction on the desk, the pointer displaces correspondingly on the screen of the computer B. However, the screen operation using the mouse C has been limited to be two-dimensional. This also applies to the other data input devices of the swine kind, such as digitizers.
As shown in FIG. 16, in the simultaneous processing, such as multitask processing or multiwindow processing, windows a, b and c to be processed are displayed so as to overlap with each other on the screen. In this case, it is necessary to open the windows in sequence from the uppermost window. This complicates the operation and further tends to induce the operation errors when controlling a number of the windows. Thin has been resulted from the fact that the conventional data input devices can only achieve the two-dimensional data inputting, and thus the offered software should correspond to such two-dimensional data inputting.
On the other hand, in the CAD (computer aided design) employed in the construction machine designing or the like, the three-dimensional data inputting has been popular. However, since the conventional data input devices can only support the two-dimensional data inputting, functions provided by the CAD can not be fully utilized, thereby causing inconveniences in operation.
Therefore, it is an object of the present invention to provide an improved data input device which is capable of inputting three-dimensional data into a computer with a simple structure.
According to one aspect of the present invention, a three-dimensional data input device for a computer having a display screen, is provided. The device includes a ball rotatably provided in a device body; sensor means for detecting rotation magnitudes of the ball along first and second axes on a plane and outputting displacement signals indicative of the rotation magnitudes, respectively; an angular velocity sensor for detecting an angular velocity of the device body about a third axis extending at a given angle relative to the plane and outputting an angular velocity signal indicative of the angular velocity; switching means for outputting a selection signal in response to operation of at least one of selection buttons; and data processing means for deriving displacement data based on the displacement signals and angular data based on the angular velocity signal and outputting the displacement data the angular data and the selection signal to the computer. The computer moves a corresponding object on the screen on a plane corresponding to the displacement data and rotates the corresponding object corresponding to the angular data about one of given axes selected by the selection signal.
It may be arranged that the first, second and third axes are orthogonal to each other.
It may be arranged that the number of the given axes is three which art orthogonal to each other.
It may be arranged that the selection signal further functions so as to perform zooming of the corresponding object on the screen.
According to another aspect of the present invention, a three-dimensional data input device for a computer having a display screen, is provided. The device includes a plurality of angular velocity sensors arranged on a plurality of axes, respectively, the axes being positioned so as to have a given angle therebetween, each of the angular velocity sensors detecting an angular velocity about the corresponding axis and producing an angular velocity signal indicative of the detected angular velocity; and angular data generating means for producing angular data each indicative of a rotation angle about the corresponding axis, based on the corresponding angular velocity signal and further based on the angular velocity signal relative to the axis other than the corresponding axis. The computer rotates a corresponding object on the screen corresponding to the angular data.
It may be arranged that the angular data generating means includes means for converting each of the angular velocity signals into a digital signal having a constant amplitude for a given time period, and a coordinate conversion section far converting each of the digital signals to a coordinate signal corresponding to a rotation magnitude of the corresponding object on the screen.
It may be arranged that the angular data generating means includes: a signal branching section for branching each of the coordinate signals into at least two; a plurality of filters for removing different frequency components from the branched signals of each of the coordinate signals; a signal combining portion for combining the branched signals of each of the coordinate signals outputted from the filters to produce a combined signal; and means for producing each of the angular data based on the combined signal, and that each of the angular data is fed to the coordinate conversion section as a conversion parameter and as the angular velocity signal relative to other than the corresponding axis, so as to be used upon conversion to the coordinate signal.
It may be arranged that the angular data generating means includes means for determining no occurrence of the angular velocity about the corresponding axis when variation of angular components contained in the corresponding angular velocity signal is within a preset dead zone of the angular velocity sensor.
It may be arranged that the angular data generating means includes temperature correction means for correcting each of the angular velocity signals based on a monitored temperature around the angular velocity sensors.